Electrically-actuated sound producer



April '28, 1925.

B. SCOTT ELECTRICALLY ACTUATED SOUND PRODUCER 2 Sne'ts-Sheet 1 Filed Aug. '51; 1922 Snom/woz a.'A

April' 25, 19.25.` 1,535,550 B. SCOTT ELECTRIC-ALLY ACTUATED SOUND PRODUCER Filed Aug. 31, 1922 2 Sheetsfheet 2 o SX1. muanofas Patented Apr. 28, 1.925.

i "r En ST i,s35,5so

i l NT F i ELECTRICALLY-ACTUATED SOUND PRODUCER.

IApplication ledAugust 31, 1922A t and State of New York, have invented-certain new vand useful Improvements in Elec- Serial No. 585,584.

vblock attached to the free end of the permatrically-Actuated Sound Producers, of which V the following is a specification sufcient to enable those skilled in the art to which the invention appertains to utilizethe same.

W'hile applicable to electrically actuated sound producing and amplifying devices for various other purposes, my invention is designed primarily for use in conjunction with what are known generally as loud music or talking receivers of the magnetic or electro-magnetic type, my main object being to atta-in a simple and'inexpensive operative device of this character in which 2G accurate adjustment of the area of an open magnetic gap may be effected with facility, and extraneously, substantially in the manner and for the reasons hereinafter fully set forth..

in the accompanying drawings, lf illustrate apractical embodiment of theessential features of my invention, although ll do not limit myself to the identical form and con? struction offpa-rts shown, since modifications in minor details, or equivalent mechanical expedients may be resorted to, without departing from the spirit and intent of my invention in this respect, and with likeA results. 'With thisy understanding, i

Fig. l,l is an exterior elevation of my elec-` trica-lly actuated sound producer;

Fig. 2, is a central vertical sectional elevaattached to the cup plate Cf, by screws c3, c,

c, formed with the inturned flange z",

tion thereof, taken upon plane of line 2 2,

Fig. 4;

Fig. 3, is a central vertical sectional elevation thereof, taken upon plane of lines 3 3, Figs. 1 and 2; l

Fig. 4:,is a transverse section taken upon plane of line 4 4, Fig. 2;

Fig. 5, is a perspective view-of the elastic j resilient 4 conversion diaphragm;

Fig. 6, is a perspective View of the permanent magnet;

Fig. 7 is aperspective'view lof the vibratory armature and its supporting spring Plate;

Fig. 8, is a perspective view of thetwo blocks upon andbetween which the armai ture spring plate is mounted;

Fig. 9, is a perspective view of the bearing nent magnet;

Fig. 10, is a perspective view of the tie rod by which the armature and the con? verter diaphragm are positively connected so as Yto vibrate in unison; A

Fig. 11, is a sectional elevation of the vlower portion of my sound producer show ing a modification in the means provided for the adjustment of magnetic gap between armature and coil core.

Fig. l2, is a detail view illustrating a modication of the meansl of gap adjust:- ment shown in Fig. l;

Fig. 13, is a sectional detail of a modification in the form of armature;

. Fig. 14, is a sectional detail of a modification ofthe means of magnetic gap adjustment. v

C, represents the main shell or casing, preferably although not necessarily, of cy# lindrical configuration with a bottom plate c, formed, in the construction illustrated in the first four gures of the drawings, with two openings, one, c', for the accommodation of the electric circuit wires connected with core-coil E, the'other, c2, for the intru-l sion of the head s, of the adjusting screw S. `The upper edge of the casing C, is rigidly til) or equivalent means, said cup plate C', being male screw-threaded peripherally for engagement with the corresponding female screw thread on the annular clamping ring 9U which bears against the external edge k, of the cap plate K,between the inner circumferential edge of which, and the upturned edge c", of the cup plate C', the sound conversion diaphragm. D, is peripherally supported las shown in Figs. 2 and 3 of the drawings,-the edge of said diaphragm. D, being provided with the 'usual binding gasket g, and the mounting and support Aof the diaphragm D, being also otherwlse essentially the same as heretofore known in the art. f

The under side of the cap plate K, vis recessed as at lc, to yafford the necessary scope' of vibration for thediaphragm D, in action; and said cap plate K, is also fprmed or rovided with the throat duct c, with wiich the .base ofthe horn H, (indicated by dotted lines in Figs. 1 and 2)Y is connected.

The upper arm m, of the U-shaped or U0 against the head r', as indicated in Figs. 2-

magnet M, is mounted the electro-magnetic core e, and its coil E, by any suitable means,

as by rigidly supporting the core e, by andl between flanged base plates fm?, m2, affixed to the upper side ofsaid free lower arm m, of the magnet M, as indicated .particularly in Figs. 2, 3, and v11, or by equivalent mechanical expedients.

The armature A, is supported upon mount ing blocks a, a', rigidly secured to the upper arm m, of the permanent magnet M, and to the cup plate C, or otherwise supported in fixed medial ,relation to the permanent magnet M, and coil IQ so as to position the said armature A, in proper juxtaposition to the core e, of the said electric coil E. For this purpose the armature A, may be provided with an elastic resilient leaf spring ax; or in certain cases, the fiat elastic resilient spring a", may itself be utilized to function as the armature A, as indicated in Fig. 13, as for instance where a loud sound is not desirable.

In either case the armature A, is rigidly connected with the sound-conversion diaphragm D, by a tie rod in such manner` single gap area between said core c, andthe.

said armature A, as herein set forth.

The tie rod R, consists preferably of a relatively thin narrow flat strip fr', as shown in detail in Fig. 10, its upper extremity being attached to a head r', formed with a screw stud r2, for engagement with a nut raf-said screw stud r2, protruding through the central perforation d, in the diaphragm I), and the latter being clamped by the nut r3,

and 3 of the drawings. rIhe flat.4 plane 0f the rod strip r, is positioned at right angles to the plane of flexure .of the armature A,

so as to allowthe stripgr, to bend easily,v

and thus neutralize as far as possible the side strain.

The lower extremity of the strip r, of the tie rod R, extends through a transverse slot a2, in the arm a, ofthe armature A, and is clamped to said arm a3, by means .of a set screw 0,4, which also affords a convenient means whereby the distance and tension between the armature A, and the 'diaphragm D, may be regulated and setwith accuracy.

Both the upper arm' m,.of the permanent magnet M, and the cup plate C', are, of course formed with openings for the accommodation of the tie rod R, as shown in Figs.

2 and 3, By this means of connecting they area of gap, and regulate the same with acy curac'y, I provide means whereby the lower arm m, of the permanent magnet M, may be forced toward the upper'Y arm m, thereof, thereby raising the electro-magnet E, and

its core e, as related to the normal position of the armature, which is prescribed by the mounting thereof on the said u per fixed arm m, of the permanent magnet` I'.

This`adjust1nent of gap between core e, and armature A, may obviously be effected by various mechanical expedients, two of which are shown by way of exemplification iu the drawings. Thus in Figs. 1, 2, 3, and

14 thereof, I illustrate the use of a non magnetic adjusting screw S, for the purpose,V

whereas in the modification shown in Fig. 11, wan eccentric S", is employed for` the same purpose. y

In the case of the non-magnetic screw S, shown in Figs. 2 and 3, its upper extremity is formed with a micrometer thread s, for engagement with a female screw thread formed for the purpose in the block a', which supportsthe armature spring plate ax, the lower extremity of said screw S, being provided with a manipulative head s', having a shoulder s2, which bears either directly against the lower arm m', of the magnet M,

as shown in Fig. 12, or indirectly against said lower arm m', through the medium of a washer s3, contacting with a bearlng block m, attached to the under side of said lower arm m', `of the magnet M, as .shown vmore particularly in Figs. 2 and 3 of the draw. lngs.

In the simpler construction shown in Fifr. 14.-, the inner end of the adjusting screw simply bears, either directly, or indirectly, against the lower arm m', of the permanent magnet M.

Thus by turning the screw S, in either direction by ymeans of its manipulative head s', positioned extraneously of the casing C, the single magnetic gap between core @,and armature A, may be conveniently regulated with accuracy; or a like result may be attained by turning the eccentric S", (Fig. l1)

on its pivotal -support by means of the' extraneous handle s", which latter may be provided With a spring detent s", :for engagement with a rack 8X2, concentric as'related to the pivotal support of the eccentric S".

In either case the same result may be attained, in that the distance between the lower arm m', of the permanent magnet M, and the upper arm m, thereof may be varied to adjust the electro-magnet E, and its core e, in position as related to the normal position of the vibratory armature A, for the purpose herein set forth.` Furthermore, this is accomplished extraneously in a simple manner, Without opening up the casing or other'- wise disturbing the operative parts vcontained therein, the device, in a unitary sense, remainingintact under all conditions and requirements of use.

The amplifying power scope of the sound producing diaphragm attained by the combination of permanent magnet and electromagnetic core as related to the vibratory armature as herein set forth, is obvious to those conversant with the art to which my invention and dev-ice appertains, as well as the various practical uses to which the device may be applied.

l have thus far ldescribed the construction and function of the operative parts in utilizing the expansive force of the permanent magnet as fixing the maximum of magnetic gap between armature and electromagnetic core, and the adjusting means as used to press the free arm of the permanent magnet toward the fixed arm thereof, for the purpose of contracting the gap area, although it is obvious that the reverse or alternative method may be resorted to with like result. rlhat is to say, the minimum of gap between armature and core may be at' tained by the contractive tendency of the "permanent magnet and its arms, and the 4may be restricted within safe adjusting means be used to retract the free arm m', as related to the fixed arm m, in order to increase the area of said gap.

In either case the extent of adjustment bounds b`y means of a stop or stops.

What ll claim as my invention and desire to secure by Letters Patent is,-

l.4 In an electrically actuated sound` producer of the character designated, the combination of a permanent magnet formed with essentially parallel-arms, one of which is fixed and the -other relatively free, an electro-magnetic coil and core mounted on the free arm of said permanent magnet, an armature mounted in prescribed relation to the fixed arm of the permanent magnet and connected with a]` sound converting diaphragm, said diaphragm, and means for adjusting the free arm of sald permanent magnet Wi-th relation to the fixed arm thereof, for

electro-magnetic coil and core mounted on the free arm of said permanent magnet, an armature mounted in prescribed relation to the fixed arm of the permanent magnet and connected with a sound converting diaphragm, said diaphragm, and means for adjusting the freearm of said permanent magnet with relation to the fixed arm thereof for the purpose of regulating the mag' netic gap between the electro-magnetic coro and said armature, comprising a set screw coupling the free arm of said permanent magnet with the ixedblock dn which the said armature is mounted, substantially in 4,the manner and for the purpose set forth.

3. In an electrically actuated `sound producer of the character designated, the combination of a permanent magnet formed with -essentially parallel arms, one of which is fixed and the other relatively free, an electro-magnetic coil and coremounted on the free arm of said permanent magnet, an armature mounted in prescribed relation to the fixed arm of the permanent magnet and connected with a sound converting diaphragm, said diaphragm, and means for adjusting the free arm of said permanent magnet with relation to the fixed arm thereof for the purpose of regulating the magnetic gap between the electro-magnetic core and said armature, comprising a set screw coupling the free arm of said permanent magnet with the fixed block on which the said armature is mounted, and the connection between said diaphragm and said armature consisting of a relatively thin fiat tie/rod arranged with its flat plane substantially at rlght angles to the plane of flexure of the armature, as and for the purpose set forth.

4. In an electrically actuated sound producer of the character designated, the combination of a permanent magnet formed with essentially parallel arms, one of which is fixed and the other relatively free, an electro-magnetic coil and core mounted on the free arm of said permanent magnet, an armature flexibly. mounted on the fixed arm of said permanent magnet and connected with a sound converting diaphragm, sa1d diaphragm, and means for adjusting the free arm of said permanent magnet with relation to 'the fixed arm thereof, for the purpose of regulating the magnetic: .gap

between the electro-magnetic core and said armature, substantially in the manner and for the purpose set forth.

5. `In an electrically actuated sound produeer of the character designated, the combination of a permanent magnet formed p with essentially parallel arms, one of Which is fixed and the other relatively free, an elettro-magnetic coil and core mounted on the free arm of said permanent magnet, an armature flexibly mounted on the fixed arm of said permanent magnet and connected with a sound eonvertingdiaphragm, said BURTON SCOT'I.

Witnesses:

MARGARET K. HANSTETN, Gro. WM. MIATT. 

